New York City Police Commissioner Ray Kelly traveled to Providence, RI, on Tuesday to deliver the annual Noah Krieger ’93 Memorial Lecture, free and open to the public.

He never had the chance to speak. An uncivil and overweening group in the audience interrupted the proceedings, refusing to let Kelly speak. The organizers, unable to bring order to their own event, canceled it after a half-hour of catcalls and shouting.

Kelly headed back to New York City without having spoken a word.

This is just plain wrong on so many levels. I write this as, to the best of my knowledge, the only person who has both reported directly to Ray Kelly at the NYPD (as deputy commissioner of counterterrorism) and been a faculty member at an Ivy League university (Harvard Univerity’s John F. Kennedy School of Government).

First off, the man himself.

Forget for the moment whatever you think of Ray Kelly’s particular policies or programs. Public service in America today can be unpleasant, unpopular and largely unprofitable. It is nonetheless essential to the success and even the survival of our republic. And Ray Kelly entered public service at the age of 19 when he became an NYPD cadet in 1960, before some parents of current Brown students would even have been born.

He is the only person ever to have held every rank in the NYPD — along the way, having also served in the US Marine Corps, the Customs Service, Interpol and at the United Nations.

Ray Kelly has been in public life continuously, with just one brief interruption, for half a century. How many living people can you name who have done that?

Today, too few people dedicate themselves to public life. Those few who do, serving with honor and integrity for decades, deserve, if not our respect, than at least our civility — and certainly not the jeers of a mob.

The Brown students who shouted Kelly down Tuesday, with tuition of $44,600 per year, would do well to remember what every starting NYPD officer — earning $44,744 per year — under Kelly’s command knows intuitively.

Second, the issues — and the role of a university. Ray Kelly has spent years in the crucible of some of the hardest issues of his time: the Vietnam War, where he was literally in the trenches; the corruption of the NYPD exposed by the Knapp Commission; urban decay, crack cocaine and an epidemic of violent crime; America’s response to 9/11 and the threat of terrorism. These are genuinely hard problems. Anyone who thinks there are easy answers is a fool.

Ray Kelly has grappled with these problems and continues to do so to this day. His approach has been lauded in many quarters, criticized in others. He argues that he has results — lives saved, attacks prevented; his critics largely argue that his ends don’t justify his means.

These are complex, important questions. They deserve to be studied, argued over, contested. The ideal venue for such debate should be a great university, where divergent opinions can be expressed and the primary sources of public-policy knowledge — the practitioners — heard.

I suspect Ray Kelly thought Brown University was such a place. Tuesday, at least, it was not.

“What is the matter with universities,” according George Bernard Shaw, “is that the students are schoolchildren, whereas it is of the very essence of university education that they should be adults.” Shaw, writing in 1909, foresaw exactly how Brown University abased itself yesterday.

Richard A. Falkenrath is a former deputy commissioner of counterterrorism at the NYPD, deputy Homeland Security adviser to President George W. Bush and assistant professor of Public Policy at Harvard’s John F. Kennedy School of Government (1998-2003).